1. Field of the Invention
The invention is a system for determining the resistance value of an earth electrode.
2. Description of the Prior Art
It is known that the true resistance of a ground bed can be measured by circulating a current between the bed and a spaced auxiliary current probe. This valve is then used in conjunction with the value obtained from an auxiliary voltage probe--placed about 62 percent of the straight line distance from the ground bed to the auxiliary current electrode--to determine the resistance by dividing the voltage by the current. We utilize this same basic principle but improve on it by incorporated several novel features.
The two known United States patents having the nearest functional similarly to our invention are the U.S. Pat. Nos. 2,260,234 (G. B. Rolfe) and 2,375,022 (G. V Morris et al). However, even these patents differ from our invention in that they cannot measure the resistance of a ground-bed on a multiply-connected (i.e. parallel) grounding system and they require continual operator activity to get the desired result. Thus, we believe that our invention is the first capable of providing continuous ground resistance records for a multiply connected system.